| 摘要 |
<p>According to the invention, a) at least the first and second compositions of this material in the fluid phase are prepared, b) a sheet (61) of the first composition is poured continuously onto a flat support (4), c) a sheet (62) of the second composition is poured continuously onto sheet (61) of the first composition, and d) the thermal interdiffusion of the materials of the two sheets is ensured so as to obtain the desired gradient of composition in the cooled bar.</p> |
